Debt and Other Obligations (Details) (USD $)	6 Months Ended
	Jun. 30, 2013 Bank	Jun. 30, 2012	Dec. 31, 2012
Debt Instrument [Line Items]
Long-term Debt	$ 134,324,000		$ 135,133,000
Long-term Debt, Current Maturities	1,420,000		1,420,000
Capital Lease Obligations, Current	235,000		228,000
Credit Facility, Maximum Borrowing Capacity	150,000,000
Number of banks in syndicate for credit agreement	9
Debt Instrument, Maturity Date	Dec. 31, 2016
Accrued Patronage Refunds	353,000	345,000
Interest Rate Swap Agreement [Member]
Debt Instrument [Line Items]
Amount of interest rate swaps	72,000,000
Minimum [Member] | Interest Rate Swap Agreement [Member]
Debt Instrument [Line Items]
Percentage of credit facility required to be covered with interest rate swaps (in hundredths)	50.00%
Period end date interest rate protection must exist on term loans	Aug. 11, 2013
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility, Maximum Borrowing Capacity	30,000,000
Debt Instrument, Unused Borrowing Capacity, Amount	29,980,000
Term Loan B Facility [Member]
Debt Instrument [Line Items]
Credit Facility, Maximum Borrowing Capacity	120,000,000
Credit Facility, Amount Outstanding	115,900,000
Debt Instrument, Periodic Payment, Principal	300,000
Incremental Term [Member]
Debt Instrument [Line Items]
Credit Facility, Maximum Borrowing Capacity	22,000,000
Credit Facility, Amount Outstanding	19,725,000
Debt Instrument, Periodic Payment, Principal	55,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Credit Facility, Amount Outstanding	$ 20,000